Recently, housings of electronic components, automotive components and the like complexly require various properties. In addition, plastic exterior products capable of realizing various colors are used as the housings. Further, these plastic exterior products can provide a more luxurious appearance to consumers by realizing a metallic texture on a surface thereof. To realize a metallic texture on the plastic exterior products, there is a method in which a molded article is manufactured from a plastic resin, followed by painting with a metal or metallic paint.
However, a metal-painted molded article has problems such as a complex process for painting, use of harmful solvents, and high manufacturing cost. In addition, when a painted plastic exterior material is used, there is a problem in that the painted plastic exterior material exhibits sharply deteriorated appearance quality since a painted portion thereof suffers from scratches even by slight impact.
To solve such problems, metal particles or the like can be added to a resin, whereby a molded article can exhibit an appearance of a luxurious metallic texture. Japanese Patent Laid-Open Publication No. 2001-262003 discloses a resin composition using scaly metal particles. Japanese Patent Laid-Open Publication No. 2007-137963 discloses a resin composition using glass fibers and metal particles. However, there is a problem in that the resin compositions disclosed therein can suffer from flow marks, weld lines or the like upon injection molding and thus can exhibit deterioration in appearance.
Therefore, there is a need for a thermoplastic resin composition for exterior materials capable of preventing flow marks and weld lines, which can occur upon injection molding and capable of providing improved gloss and appearance properties while maintaining original properties of a thermoplastic resin. In addition, there is a need for metal particles capable of realizing an appearance close to metal-painted products even without painting.